Understand better now - sorry.
If it ran on Monterey 12.0 which must have been it version installed on a Brand New Apple computer.
The very first Public Release for upgrades to Monterey was version 12.01.
Then on December 13, 2021 an update Monterey 12.1 was released.
It may have run initially on 12.0 but the updates must have introduced some additional Security and Big Fixes that make this software not function any longer.
That or three things;
1 - Re-download the dmg and try again
2 - Contact the Developer of this software and inquire for a Compatible version of Monterey 12.1
3 - Wait around for " More Learned Colleagues " to pickup this question and they may have more insights or solutions to offer.